(p, n) Reactions inMn55,Co59,Zh67, andZn68

The counter ratio technique has been applied to the study of ($p, n$) thresholds in ${\mathrm{Mn}}^{55}$, ${\mathrm{Co}}^{59}$, ${\mathrm{Zn}}^{68}$, and ${\mathrm{Zn}}^{67}$. The ground state thresholds were found at proton energies of 1.895±0.005 Mev for ${\mathrm{Co}}^{59}$, 3.762±0.005 Mev for ${\mathrm{Zn}}^{68}$, and 1.805±0.005 Mev for ${\mathrm{Zn}}^{67}$. Thresholds were found corresponding to excited states in ${\mathrm{Fe}}^{55}$ at 0.924, 1.327, 2.16, 2.554, 2.92, and 3.76 Mev; in ${\mathrm{Ni}}^{59}$ at 0.325, 1.195, 1.776, 2.551, 3.043, 3.543, and 3.340 Mev; in ${\mathrm{Ga}}^{68}$ at 0.188, 0.342, 0.574, and 0.848 Mev; and in ${\mathrm{Ga}}^{67}$ at 0.357, 0.85, and 1.54 Mev. Absolute cross sections were measured for neutrons at 0° to the incident beam.